Floating dry dock



G. C. ENGSTRAND.

FLOATING DRY DOCK.

APPLICATION man JULY 19.1921.-

Panted Apr. 118, 1922.

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GUNNAR C. ENGSTRAND, OF BROOKLYN, NEW YORK.

FLOATING DRY DOCK.

ifiiaeea Application filed July 19,

My invention provides side pontoon shelves for dry dock sections on which shelves the ends of other dry dock sections can be readily supported and the section raised clear out of the water.

My invention also provides locking means to prevent the supported section from slipping off the pontoon side shelves.

In the drawing Figure 1 shows the detail construction of the side pontoon shelves.

Figure 2 shows in a. diagrammatic. way the docking of a dry dock section.

Referring to the drawing in which like reference characters designate corresponding parts, 1 and 1 represent the dry dock sections, each of which comprises a pontoon part 2 with a side wall 3 at each end.

The framing of the pontoon 2 comprises double flanged steel stringers l between which a series of uprights are clamped and to which stringers the deck and bottom planking 9 are bolted.

The wing uprights 5 are also clamped between the double hanged stringere 4 and these uprights 5 extend from the bottom of the pontoon. 2 to the top of the wing 3.

The fianged stringers il extend past the wing uprights 5 and are supplied with flanged corner brackets 6 between which the pontoon side uprights 7 are clamped. The pontoon side planking 8 is secured to the uprights 7 in a conventional manner.

rl`he corner plank l0 of the bottom planking is made heavier so as to project below the remaining bottom planking,

The top of the pontoon side shelf 15 is covered with the shelf planking 11, on which planking blocking 12 is mounted.

The cleat 13 is provided in order to engage the projecting bottom plank 10 and thus prevent the end of the supported section 1 to slip off the blocking.

The weight of the supported section 1 is Specification of Letters 'Patent Patented Apr. 18, 1922.

1921. Serial NO. 485,871.

counter balanced by means of sufficient ballast water on the opposite side of the center b-ulkheads 14 of the supporting sections 1. All the three sections engaged in the self docking are thus'kept levelled.

The procedure of self-docking is as follows The section 1 which is to be docked is pumped out and the sections 1 which are to act as supports are lowered until the blocking 12 is well below the bottom of the section 1.

The sections are now brought together in the relative position shown in Figure 2 and the sections 1 are pumped out.

1n pumping out these sections the sides which are to support the section 1 are pumped out more quickly leaving at the end ofthe operation sufficient bilge water -on the opposite side of center bulkheads 14;, all as shown in Figure 2.

7hen the docked section is brought sufficiently out of the water, the repairs are made.

The repairs completed the procedure is reversed and the three sections are again conveniently combined into a fioating dry dock.

l claim:

1. In a floating dry dock, wing uprights extending from the bottom of the pontoon to the top of the wings, pontoon bottom and deck stringers extending past the wing uprights and permanently attached thereto and at their ends secured to separate pontoon side uprights thus forming a pontoon side shelf, substantially as describedA and for the purpose set forth.

2. ln a floating dry dock, sections the wings and pontoon of which are built integral, said sections having lateral pontoon side shelvesa substantially as described and for the purpose set forth.

3. In a floating dry dock, sections the wings and pontoon of which are built integral.v said sections having lateral pontoon side shelves and means to lock in position any section supported on said side shelves of two of the remaining sections, substantially as described and for the purpose set forth.

GUNNAR C. ENGSTRAND.

Witnesses FREDERICK W. QUmAs, FRANK Nicnots. 

